Highway crossing signaling device



Sept. 25, 1951 I M|LLER 2,569,111

HIGHWAY CROSSING SIGNALING DEVICE Filed Aug. 31, 1949 9 ile /fl% y Patented Sept. 25, 1951 UNITED STATES PATENT OFFICE HIGHWAY CROSSING SIGNALING DEVICE Frank P. Miller, Chicago, Ill.

Application August 31, 1949, Serial No. 113,301

7 Claims. (Cl. 246-126) This invention relates to improvements in signaling devices for railroad crossings and refers particularly to a signaling device for warning the operator of an approaching train that a motor vehicle or the like is stationary on the right-ofway at the crossing.

One of the important features of the present invention resides in its simplicity in operation and its economy of installation, necessitating only a minimum of auxiliary equipment over and above that already existing at automatically guarded crossings.

A further important feature of the invention resides in a signaling device, the source of power for which may be obtained locally as a part of the crossing installation or may be carried by the train.

Another important feature of the invention resides in a signaling device in which the elements for actuating the system are few and can be so constructed and installed so as to function reliably substantially independently of adverse weather conditions.

In the drawings,

Fig. l is a diagrammatic view illustrating the Wiring system for my improved crossing signal.

Fig. 2 is a top plan view of the crossing.

Fig. 3 is a sectional view taken on line 33 of Fig. 2.

Fig. 4 is an end elevational view illustrating the rockable mounting of the crossing grating.

Referring in detail to the drawing, with specific reference to Figs. 2, 3 and 4, indicates a pair of railroad rails. Between the rails I-I Where a highway may pass over the right-of-way a grating 2 is positioned. The grating 2 may comprise a plurality of bars 3 which are conveniently constructed of metal and may be disposed edgewise in spaced relationship to each other. The bars 3 may be secured together at their ends by tie rods 4 and said bars may be spaced from each other by means of spacers 5.

A pivot rod 6 is positioned through the central portion of the grating 2, said rod passing through all of the bars 3 constituting the grating. The rod 6 is journalled in spaced supports 1 which may be mounted intermediate the rails |I. The arrangement is such that the grating, as a Whole, is pivotally supported upon rod 6 whereby a vehicle moving onto the grating will rock the grating about the pivot rod 6. Coil springs 8 support the opposite ends of the grating and normally position the grating in a horizontal plane. A contact bar 9 is disposed parallel to each rail l and is positioned beneath the ends of the bars 3 2 constituting the grating. An electrical conductor I 0 connects each contact bar 9 to its adjacent rail I.

When a vehicle moves over the gratin 2 the grating will be rocked about the pivot rod 6 and one end or the other of the bars 3, depending upon in which direction the vehicle passes or upon which side of the pivot rod 6 the greater portion of the vehicles weight is positioned, will be depressed whereby bars 3 will be brought into contact with one or the other contact bars 9. Under normal circumstances when no vehicle is positioned upon the grating the sprin s 8 serve to maintain the grating in a horizontal plane with both ends of the grating spaced from the contact bars 9. For purposes of illustration, coil springs are shown as the means for maintaining the grating in its balanced or neutral position. It is to be understood, of course, that leaf springs may be employed if so desired for accomplishing the same purpose.

Referring particularly to Fig. 1 my signaling system is illustrated as being applied to a pair of tracks. Of course, it is to be understood, that as many tracks as desired may be guarded in the fashion to be hereinafter more fully described.

In Fig. 1 the crossing is designated generally by the reference numeral II, the highway crossing the tracks I at substantially right angles. As auxiliary equipment in carrying out my invention, a third rail I2 is positioned between each set of rails comprising a track. The third rail [2 may comprise a metallic rail of relatively light gauge and may extend an appropriate distance down the track from the crossing sufficient to permit the operator of an oncoming train to manipulate his brakes and stop the train before it reaches the crossing. The specific distance that the third rails I2 will extend from the crossing, of course, will depend upon the nature of the traffic of the railroad, that is, if high speed passenger trains move on the tracks the third rail l2 will extend a greater distance than if the tracks are employed only for slow moving freight. Of course, the third rail extends away from the crossing in a direction toward the oncoming train. If, however, traffic upon the tracks moves in both directions on the same set of tracks the third rail will extend an equal distance beyond each side of the crossing.

Signaling devices l3 comprising a bell I4 and light I5 are positioned upon each side of the crossing both devices l4 and I5 being connected in parallel across one of the tracks I and the third rail I2 by means of conductors I6 and I! respectively. Of course, if desired electrically operated crossing gates (not shown) may also be connected in parallel with the signaling devices I4 and I5 and may be simultaneously operated with said signaling device in the manner to be hereinafter more fully described. A resistance I8 is interposed in conductor I9 which connects the bars 3 to the third rail I2.

A control system is employed'in conjunction with my signaling device and is carried'by the locomotive which operates upon the tracks I. The control system comprises a source of electrical energy which for purposes of i1lustration comprises a generator 2I. If desired, the generator 2I may be replaced by anyothersource of electrical power such as storage batteries or the like.

The control system 20 comprises a signal light 2I which may conveniently be of amber color, a redlight 22 and .a bell :23. In addition the arrangement 20 mayinclude a relay switch 24. The relay switch 24 comprises a relay coil 25 and armature 26.

One side of the source ofpower 2| may be connected to the third rail I-2 as shown diagram- -matically in Fig. ;1 bytheconductor 2'I. vIf the generator or othersource of power 2I is carried .means ofconductor28 shown diagrammatically;

in Fig. l. The amber light 2 I is connected across therelay coil 25 by means of conductors 29. The red light 22 and bell 23 areconnected in parallel .with each other and are connected across the source of power 2I by means of conductors 30 and 3I. Interposed in conduct rjI is the relay swit h 24 h ri ctuaies in a manner to be h re n me i ul e c ibed- The operation of my dev iceisasfollowsz With a train approaching the crossing II and with no vehicle positioned upon the grating 2 the signaling device I3 at the crossing will beactuated. As the train approaches the crossing the generator 2I which may be carried by the locomotive is in constant operation and the shoe carried by the locomotive makes contact with the third rail I2 thus providing the electrical path diagrammatically designated as 21. The wheels of the locomotive, of course, are in contact with the rail I and the said wheels are grounded to the opposite side of the generator 2I thus completing the electrical connection diagrammatically designated as 28. When the connections 21 and 28 are thus made current will pass from the generator 2| through the connection '2! to the third rail I2. Current will therefore pass through the signaling devices I4 and I 5 located at the crossing and said current will be returned to the generator through the connection 28 and the amber light 2| which is positioned in the locomotive cab.

The fact that the amber light is illuminated will indicate to the operator that a crossing is being approached and that the signaling devices at the crossing are in operation. The relay coil 25 is connected across the amber light 2I and consequently a predetermined current will pass through said relay coil. However, the current drawn by thesignaling devices I4 and I5 at the crossing is insufficient to actuate the relay switch 24 which is normally open and consequently the signaling devices 22 and 23 will not be connected in the generator circuit.

If, however, a vehicle is stalled upon the grating 2 and the train approaches the crossing II, the grating will be so rocked as to connect bars 3 and rails I through the resistance I8. Current will then not only pass through the signaling devices I4 and I5 and amber light 2I in the manner hereinbefore described but current will also pass from the third rail I2 directly to the rails I through the resistance I8. It can readily be seen, therefore, that the current drawn by the apparatus at the crossing is increased and there- :fore thecnrrent passed through the relay coil 25 increases. With the increased current passing throughthe relay coil 25 the relay switch 24 is ,closed thereby connecting the red light 22 and bell'23 in the operators cab in circuit with the generator 2I thereby warning the operator that a vehicle is stalled upon the crossing I I and per- -mitting the operator to take the necessary steps in applying brakes etc.

It can readily be seen that the relay switch is of such character that it will be actuated by a predetermined minimum current and when said minimum is exceeded the switch closes. In addition, the resistance I8 is of such value that the signaling devices I4 and I5 will not be shorted out of circuit but will still be operative even though the additional contacts are made by reason of the stalled vehicle upon the grating.

One of the features of my invention resides in the fact that a single circuit is employed to perform the two operations hereinbefore described, that is, to actuate the signaling devices at the crossing in a normal manner and to additionally furnish a signal to the operator of the locomotive when a vehicle is stalled upon the crossing. Consequently, only one additional rail is necessary for each set of tracks and in view of the fact that the total current carried is compartively small and also that relatively low voltages may be employed, the necessity for heavy contact equipment and heavily insulated devices is avoided. The additional contact members at the crossing comprising the bars 3 and contact rails 9 can be of extremely rugged construction and can be adequately protected from the elements.

It is appreciated that modifications of my invention may be made without departing from the spirit and basic concept thereof and consequently I do not wish to be limited except as necessitated by the prior art.

I claim as my invention:

1. In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried by said tracks, a source of electric current carried bysaidrailroadvehicle,athird rail carried parallel to said track adjacent a highway crossing, an external circuit comprising an electric signal positioned adjacent said crossing and connected across a rail of said track and said third rail, means upon said railroad vehicle for connecting said source of current to said external circuit to actuate said signal when said railroad vehicle approaches said crossing, electric signal means carried by said railroad vehicle, switch means for connecting said signal means to said source of current to actuate said signal means, crossing switch means actuated by a highway vehicle at said crossing for increasing the current through said external circuit, and means carried by said railroad vehicle for closing said switch means in responsse to said increase in current in said external circuit.

2. In a railroad highway crossing signalling device adapted for use with a track and a railroad vehicle carried by said track, a source of electric current carried by said railroad vehicle, a third rail carried parallel to said track adjacent a highway crossing, an external circuit comprising an electric signal positioned adjacent said crossing and connected across a rail of said track and said third rail, means upon said railroad vehicle for connecting said source of current to said ex-' ternal circuit to actuate said signal when said railroad vehicle approaches said crossing, electric signal means carried by said railroad vehicle, switch means for connecting said signal means across said source of current, crossing switch means actuated by a highway vehicle at said crossing for increasing the current through said external circuit, and means carried by said railroad vehicle for closing said switch means in response to said increase in current in said external circuit, said crossing switch means comprising a depressible switch closed by the weight of a highway vehicle, and a circuit including said depressible switch between a track rail and said third rail.

3, In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried by said track, a source of electric current carried by said railroad vehicle, a third rail carried parallel to said track adjacent a highway crossing, an external circuit comprising an electric signal positioned adjacent said crossing and connected across a rail of said track and said third rail, means upon said railroad vehicle for connecting said source of current to said external circuit to actuate said signal when said railroad vehicle approaches said crossing, electric signal means carried by said railroad vehicle, switch means for connecting said signal means across said source of current, crossing switch means actuated by a highway vehicle at said crossing for increasing the current through said external circuit, and means carried by said railroad vehicle for closing said switch means in response to said increase in current in said external circuit, said crossing switch means comprising a depressible switch closed by the weight of a highway vehicle, and a circuit including said depressible switch between a track rail and said third rail, and a resistance connected in said last mentioned circuit of predetermined ohmic value to permit a predetermined actuating current to pass through said electric crossing signal and electric signal means carried by said railroad vehicle.

4. In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried upon said track which comprises, a source of electric current carried by said vehicle, an electric conductor disposed parallel to said track adjacent a highway crossing, an electric signal positioned at said crossing and connected to said track and conductor, means upon said vehicle for connecting said source of current across a rail of said track and said parallel conductor when the railroad vehicle approaches said crossing to actuate said crossing signal, electric signal means on said railroad vehicle connectable in series with said source of current and the circuit comprising said rail and parallel conductor, an electric relay switch having a relay coil carried by said vehicle, said relay coil being connected in parallel with said signal means and relay switch, a resistance connectable between said rail and parallel conductor, and depressible means at said crossing for connecting said resistance across said rail and parallel conductor to increase the current through said relay coil and close said relay switch when a highway vehicle rests upon said depressible means.

5. In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried upon said track which comprises. a source of electric current carried by said vehicle, an electric conductor disposed parallel to said track adjacent a highway crossing, an electric signal positioned at said crossing and connected to said track and conductor, means upon said vehicle for connecting said source of current across a rail of said track and said parallel conductor when the railroad vehicle approaches said crossing to actuate said crossing signal, electric signal means carried by said railroad vehicle, switch means for connecting said signal means and said source of current, means connected in series with said source of current and said rail and parallel conductor for actuating said switch means when the current drawn by said rail and parallel conductor circuit increases above a predetermined minimum, a resistance connectable between said rail and parallel conductor, and depressible means at said crossing for connecting said resistance across said rail and parallel conductor to increase the current through said switch-actuating means above said predetermined minimum when a highway vehicle rests upon said depressible means.

6. In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried upon said track which comprises, a source of electric current carried by said vehicle, an electric conductor disposed parallel to said track adjacent a highway crossing, an electric signal positioned at said crossing and connected to said track and conductor, means upon said vehicle for connecting said source of current across a rail of said track and said parallel conductor when the railroad vehicle approaches said crossing to actuate said crossing signal, means carried by said railroad vehicle and connected in the circuit of said source of current for indicating that the crossing signal is actuated, electric signal means on said railroad vehicle connectable in series with said source or current and the circuit comprising said rail and parallel conductor, an electric relay switch having a relay coil carried by said vehicle, said relay coil being connected in parallel with said signal means and relay switch, a resistance connectable between said rail and parallel conductor, and depressible means at said crossing for connecting said resistance across said rail and parallel conductor to increase the current through said relay coil and close said relay switch when a highway vehicle rests upon said depressible means.

7. In a railroad highway crossing signaling device adapted for use with a track and a railroad vehicle carried upon said track which comprises, a source of electric current, an electric conductor disposed parallel to said track adjacent a highway crossing, an electric signal positioned at said crossing and connected to said track and conductor, means upon said vehicle for connecting said source of current across a rail of said track and said parallel conductor when the railroad vehicle approaches said crossing to actuate said crossing signal, electric signal means on said railroad vehicle connectable in series with said source of current and said rail and parallel conductor.

7 8 an electric relay switch having a relay colicar- REFERENCES CITED med said which said relay con being The following references are of record in the nested in lparaliel with said signal means and me of this patent:

relay switch, a resistance conneetable between said rail and para11ei conductor, and depressible ,5 UNITED STATES PATENTS means at said crsssing for cennecting said re- :Number Name Date :sistanca across, said rail and parallel conductor 1,535,960 Stewart Apr. 28, 1925 -.;0 increase the current through said relay coil 2,165,569 'Obermaier July 11, 1939 and-close said relay switch when a highway ve- D hicle rests. upon said depressibie-means. FOREIGN ATENTS Number Country Date FRANK P.. IVIILLER. 753,919 France Oct. 5, 1933 

